Washington: The United States on Friday authorized Moderna’s Covid-19 vaccine for emergency use, paving the way for six million doses of a second vaccine to soon begin shipping across the hardest-hit country in the world. “Congratulations, the Moderna vaccine is now available!” said President Donald Trump in his tweet.

The Pfizer-BioNTech vaccine was approved by Britain on December 2, followed by several other countries including the US last week. Less-vetted shots have also been rolled out in China and Russia. The United States alone has seen more than 310,000 people die from Covid-19 infections and is in the midst of a brutal winter surge, with nearly 115,000 people hospitalized, according to the Covid-19 Tracking Project.